Aircraft



March 7, 1933.

H. JUNKERS AIRCRAFT ,7 Filed on. 21, 1931 Patented M11137, 1933 I UNITED STATES PATENT OFFICE nueo sonxnns, or nnssau, GERMANY AIRCRAFT Application filed October 21, 1931, Serial No. 570,080, and in Germany October 28, 1930.

" If an altitude chamber leaksor the means fail for maintaining therein the normal pressure, the persons in the chamber will become unconscious or at least unable to pere i l m theilxdiltiesniIftrouble of this kin'd 5 occurs in the chamber of the pilot and he is temporarily disabled, the risk to the craft is obviously very great.

It is an object of my invention to prevent accidents due to a reduction of pressure in an altitude chamber. To this end I provide a. pressuresensitive element in the altitude chamber which is operatively connected to means for cutting out the engine if the pressure in the-altitude chamber falls below a predetermined minimum.

The means for cutting out the engine may act on any vital member thereof, for instance, on its ignition systemor on its-fuel supply. When the engine has been cut out, the aircraft, normally an airplane, starts to glide and soon'attains lower regions of higher pressure so that the persons who have become unconscious or otherwise unable to perform their duties, will soon recover and there is still time to land in safety.

The pressure-sensitive element in the altitude chamber may be of any suitable kind. In the present instance a hollow and preferably evacuated element of the kind used in 40 aneroid altimeters will be described which is so designed that it expands upon reduc tion of thepressure in the altitude chamber and, in expanding, cuts out the en ine; For instance, the hollow element itsel or mechanism connected to it, may short-circuit the ignition magnet.

The means for cutting out the engine may also be designed on the servo principle, the element or a member actuated by it operating a source of energy of any suitable kind, such as electric energy, gas or liquid under pressure, mechanically actuated gearng, or the like, by which a servo 'motor is actuated and cuts out the engine, for instance, by interrupting its fuel supply.

In the drawing aflixed to this specification and forming part thereof two embodiments of myv invention are illustrated diagrammatically by way of example.

In the drawing Fig. 1 is a section of an altitude chamber showing a pressure-sensitive element in combina tion ntith means-for short-circuiting the ignition magnet of the engine.

Fig. 2 is a partly sectional diagram of a system including a servo motor under the control of the pressure-sensitive element for interrupting the fuel supply of the engine. Referring now to the drawing, and first to Fig. 1, 0 shows a portion of the wall of an altitude chamber, a is a casing in the cham-' ber, b is an opening in the wall of the casing connecting its interior to the altitude chamber c, 'w is a threaded support adapted to fit, in a sleeve m at the top of the casing a, and (Z is a pressure-sensitive element resembling the element of an aneroid altimeter which is attached to the lower or inner end of the threaded support 00. As mentioned, the element d is preferably evacuated but this is not necessary, the condition being only that the element should be sensitive to a fall'of the pressure in the chamber 0 below a'predetermined minimum. k is the base plate of the casing a which in thepresent instance is made of insulating material for a reason which will be explained below. 6 is a bearing on the base plate 10, f is a lever which is pivoted in the hearing at one endand adapted to engage below the end of the element 03 with its other end,.r is a handle onithe pivot of the lever outside the casing a, and g is a spring which is attached to the lever f at oneend, and to the casing b at the other end, the bracket o by which this end of the spring is held, being so positioned with respect to the pivot of the leverf in the bearing e that it throws over the lever to one or to the other side of the pivot if the lever departs from its neutral position II.

k is a conductor connecting the bearing;

'ing material 'as the bearin tacting memb to the body of the aircraft, z' is a contacting member which is secured in the base plate h in line with the axis of the element d, and k is a conductor connecting the contacting memberz' to the primary coil a: of an ignition magneto M which supplies the sparking plugs of the engine (not shown). The details of the magneto form no part of the present invention and therefore have not been shown and described in detail, S

shows diagrammatically the sparking gaps at the plu s of the engine.

Obvious y it is not necessary that the base plate hof the casing a should be of insulate and the coner 2' might be lnsulated from a plate of conducting material.

In operation the element d is adjusted by means of the threaded sleeve w and under the normal pressure of the air in. the altitude chamber 0 is shortened to the length shown in full lines. The spring 9 holds the lever f engaged with the lower end of the element in the position I, while the pressure is normal. If the pressure falls in consequence of any trouble, such as leakage of the altitude chamber a, or failure of the means for maintaining the'norinal pressure therein, the elemental expands and entrains the lever f as shown in dotted lines. At II the axes of the lever f and the spring 9 coincide and a very slight expansion of the element d below this point causes overthrowing of the lever f into the position III in which the free end of the lever engages the contacting member 2' and short-circuits the primary coil :12 through 10 e, f, z and 70 The magneto M now becomes inactive, the engine stops and the airplane starts gliding automaticall so that it soon reaches lower regions of hlgher pressure in which the disabled pilot will recover and prevent an accident.

The position of the point II at which the 1 lever f is in its neutral position, may be Varied in conformity with the pressure conditions b adjusting the element d through the me ium of its threaded sup ort w. The position of the point II determines the minimum to which the pressure in the chamber c is permitted to fall before the element d starts to operate. If the pressure limit is j-understepped for the slightest amount, the

lever fis jerked from II to III and the magneto M is short-circuited as described. By

means of the handle 1- the lever f is returned into the position I after normal pressure conditions have been re-established, and held engaged with the element d by spring g.

- Referring now to Fig. 2, the casing "a with the mechanism therein is designed as described with reference to Fig. 1 but in this instance the bearing e and the contactin member 21 are connected to a circuit t, wit

interrupting the fuel suppl of the engine 11.. 3/ 1s a core which is a apted to be attracted by the coil u when the coil is excited,

and 2 is a spring which returns the core into its initial position when the coil u is de-energized. p is a fuel pump which is actuated by any suitable means, for instance, the cam indicated below its cylinder, 9 is the delivery pipe of the pump, and c is a two-way valve in the delivery pipe 9 which is operatively connected to the coil 3 In the position of parts illustrated in Fig. 2 the valve '0 opens the supply of fuel to the engine n, which may be of the Diesel type, but the lever f has just made contact at i so that in the next instance the coil 20 will be energized and attract its core 3 rotating the valve '0 through 90 degrees. In this position of the valve the connection of the pipe gwith the cylinder-of the engine is interrupted and the fuel which is delivered by the pump returns to the supply tank through the short bore of the valve which now registers with the rear portion of the pipe q and 4 desire to be lhnitedTc the exact details of" construction shown and described for obvious modifications will occur to a person skilled in the art.

In the claims aflixed to this specification no selection of any particular modification of the invention is intended to the exclusion of other modifications thereof and the right to subsequently make claim to any modification not covered by these claims is expressly reserved. i

I claim 1. An aircraft comprising an altitude chamber, a pressure-sensitive element in said altitude chamber, and means operatively connected to said element for cutting out the motive power of said craft.

2. An aircraft comprising an altitude chamber, a pressure-sensitive element in said to said element for cutting out'the motive power of said craft.

3. An aircraft comprising an altitude chamber, a pressure-sensitive element in said altitude chamber, a rocking lever adapted to be operated by said element, resilient means for jerking said lever beyond a neutral position, and means for cuttin out the motive power of said craft whic are so positioned as to be engaged-by said lever when it has moved beyond its neutral position in a given direction.

4. An aircraft comprising an altitude chamber, a magneto for the ignition of its engine, apressure-sensitive elementin said eiiimde chember and means egsemtiveiy cemeete. wish seid eiement shew-eheuieing seiei magneto 5. eirersi's comprising en altitude chamber, 21 eii'euit for csntmiiing the massive power 0i sai wait, as rocking eenteeibing lever connected to sue en sf seici circuit e eentsca cemieeted to the ethei emi 0% said ciireuit end ee otedi to be engegefii by the w free end of said racking levee a pressure sensitive element in sei altiiiucie chamber 1-. wpteci to operate swiv reeinng lever, end a spring connected "so said seeking lever which is 50 arranged as is move seiel reciting iever tswe'rd said element or said centimetin member beymfl the neutral posithion of said; lever.

6. An mil-emit comprising an eisitude chamber, e pressure-seusiiive element in serial 2% altitude ehemeer, end. meens inclmiing s servumoter end opemtiveiy eeimee'seai is said element for cutting nut she mesive pewer of said ereie,

Z. An eisrci'eft eemprising an sitiimm 35 chamber a circuit servo meter in seicircuiis, means @peretivei'" cemieceeel to said motor fer cutting the metive peeve? 0'55 said emf-t pressure-sensitive eiemem in seici altitude means epezeeive 137 connected seid element swimming said circuit.

8. Am ehember, i

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